The present invention is directed to fault detection in electrical circuits for which resistive-inductive-capacitive (RLC) loads are selectively excited by a switching device.
Fault detection and protection is required in most electrical applications. For some fault conditions, such as overvoltage faults, the simplest method of detection is to monitor the voltage and compare the monitored voltage to a threshold value. If the monitored voltage exceeds the threshold value, then an overvoltage condition is detected and protective action, such as de-exciting the system, is taken. However, this type of overvoltage detection requires dedicated hardware (e.g., voltage sensors, comparators) to detect overvoltage conditions. The same is true for other types of fault detection. For each fault to be detected, dedicated hardware circuitry is required to detect the fault, which increases the cost of the system.